Base for electric lamps or similar devices



BASE FOR ELECTRIC LAMPS OR SIMILAR DEVICES I Filed May 20, 1932 W r INVEZXZ TUE 5' 4 Y EIRQLD .ZZ BLAKE. m ml, E JE'EIGEA .33?

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Patented Jan. 5, 1937 Harold D. Blake, Cleveland Heights, and Walter J. Geiger, Cleveland, Ohio, assignors'to General Electric Company York , a corporation of New Application May 20, 1932, Serial No. 612,540

5 Claims. (Cl. 176-32) Our invention relates to electric incandescent lamps and similar devices which comprise a transparentbulb containing an electric energy translation element and a. base attached to the bulb and comprising terminal elements connected to leading-in conductors which are connected to the said energy translation'element.- More particularly our invention relates to-the means of attachment of the base to the bulb and to the con- 0 struction of the base itself including the terminal elements comprised thereby and their connections with the leading-in conductors. From one standpoint our invention has to do with a base which is attached to the bulb by inter-engagement of parts of each rather than by cement. From another standpoint, our invention relates to the construction of the base irrespective of the means of uniting it to the bulb. From the latter standpoint, and more specifically considered, our invention provides means for connection of leading-in conductors to the terminal elements of the base without soldering or welding.

Heretofore there have been cementless bases comprising a metal shell constituting a ring member united to the bulb by inter-engagement of protuberances and depressions in one or the other and another metal shell united to the said ring member. and comprising the means for attachment to a socket. As distinguished from such bases, our device comprises a single metal shell which is attached to the bulb and comprises the means 'for attachment to the socket. Preferably, we make use of the ordinary screw form of attachment and the shell is therefore threaded, portions of the thread being utilized as depressions and protuberances engaging a suitably shaped bulb neck to prevent movement longitudinally of the lamp and provide other protuberances or depressions to prevent rotation of the base on the said neck.

The shell of the base acts as one terminal to which the end of a leading-in conductor is clamped by a cap of insulating material which fits into the open end of the shell. The said cap is apertured preferably centrally thereof to allow the end of the other leading-in conductor to protrude and engage asmall metal center contact which fits into a depression in the said cap.

Various other features and advantages of our invention will appear from the description which follows of species thereof and from the accompanying drawing. v

In the drawing Fig. 1 is a side elevationof an incandescent lamp embodying our invention; Fig. 55 2 is a perspective view of the sealing-in portion of said lamp; Fig. 3 is a perspective view of said portion after the base shell has been ,applied; Fig. 4 is a side elevation of a portion of the lamp with the base shown in section; Fig. 5 is a perspective view of another species of our invention par- 3 tially disassembled and with a portion of the cap removed; and Figs. 6, 7 and 8 are side elevations of a portion of an incandescent lamp with various-species of our invention shown in section. The specific embodiment of our invention shown in Figs. 1, 3 and 4 is in the form of an electric incandescent lamp base which is attached to a tipless lamp ID of the type described in Patent 1,423,956 to Mitchell and White. The base comprises the shell H preferably of brass, alumi- 5 .num or other conductive material, the insulating cap l2 preferably of hard rubber or the like, and the metal end terminal 13; The shell I l is made from a substantially cylindrical piece of metal, the mid portion of which has been screw threaded and one rim of which has been flared outward and the other rim of which has been bent inward. Just above the flared-out portion 14 of the shell are located a series of depressions l5 which provide with the threaded section an irregular interior about which that portion of the bulb neck adjacent the seal is molded as shown in Fig.4. Our preferred method of molding the said seal portion consists in bringing the shell ll into contact therewith, preferably just after the lamp has passed through'the sealing-in fires, and then forcing air into the lamp so as to expand the plastic glass into the irregularities of the shell. Pressure is preferably applied to the shell when it is brought into contact with the seal in order to facilitate the molding of the less plastic portions of the seal. The change in the shape of the seal can be discerned by comparing Figs. '2 and 4, the former of which illustrates a newly made seal before the shell has been attached. Before the remaining parts of the'base are assembled,,the lamp must be evacuated orgasfill ed andtube I6 sealed off. r i The vend of shell is reduced to form a neck ring I I. and cap l2 fits over-said end with saidring held in a circular groove in the bottom of said cap. Said ring is corrugated to'increase the fric tion between it-and the cap and to more securely retain the latter and'has a slot l8 therein to receive the end of leading-in wire l9. Suflicient force is applied to press the cap into place and the leading-in wire I9 is held securely in contact with the shell and will not work loose. The other leading-in wire 20 is threaded through a 2i which cause the said contact to be more securely held. It is forced and sprung into a circular groove in the cap and no other means are required to hold the end of the leading-in wire in firm contact therewith.

Other species of our invention which are shown in the remaining figures differ from the above described species only in the shape of the insulating cap and the means of its attachment. In

the first of these, shell 22 is provided with a pair of upwardly extending tongues 23 which at assembly are passed through slots and their protruding ends bent down into recesses in cap 24. The end of one leading-in wire is held as before between the shell 22 and cap 24 and the end of the other passes through a central aperture in said cap and is clamped between the cap and the end contact 25. In the species shown in Fig. 6, insulating cap 26 has a bottom annular portion 21 of reduced diameter which is inserted into a reentrant sleeve 28 forming part of shell 29 while said sleeve is in an expanded condition due to the heat receivedby the said shell during its attachment to the lamp.

The species shown in Fig. '7 is essentially the same as that just described although a shrink fit is not used between sleeve 30 and cap 3i as a portion 32 of the shell 33 just above said sleeve is spun over the rim of the cap and serves to hold it in place. This type of base is particularly suitable when aluminum or other easily worked metal is used for shell 33.- The last species of our invention is shown in Fig. 8. The cap 34 in this instance is provided with a bottom portion 35 of reduced diameter which tapers inwardly and is provided with an end flange 36 which is engaged by a series of fingers 31 formed from a re-entrant sleeve portion at the end of shell 38. The fingers 31 are of sufllcient springiness so that they snap into engagement behind fiange 36 upon the insertion of the cap. The end of leading-in wire is is located between a pair of the fingers and is clamped between the shell 38 andcap 34, and the end oi leading-in wire 20 is clamped between end contact 39 and said cap.

'by said shell and a metal end contact supported by said cap, portions of said shell and tubularportion of said bulb being in engagement completely "around their inner and outer peripheries,

respectively and being provided with matched protuberances and depressions in the contiguous surfaces thereof fitting together to unite said shell directly and firmly to said bulb and to permanently locksaid shell on said bulb, and the end of one of said leading-in conductors being clamped to said shell by said insulating cap and .the end of another being electrically connected to said end contact.

2. In an electric device, the combination of a bulb having a tubular glass end portion and having mounted therein an electric energy translation element and leading-in conductors extend-1 ing therefrom of a base comprising a rigid cylindrical metal shell, an insulating cap supported by said shell and a metal end contact supported by said cap, portions of said shell'and tubular portion of said bulb being in engagement completely around their inner and outer peripheries respectively and being provided with matched protuberances and depressions in the contiguous surfaces thereof fitting together to unite said shell directly and firmly to said bulb and to permanently lock said shell on saidbulb, and 'the end of one of said leading-in conductors being clamped to said shell by said insulating cap and the end of another being clamped between said metal end contact and said insulating cap.

3. In an electrical device, the combination of a glass bulb having mounted therein an electrical energy translation element and leading-in conductors extending therefrom of a base comprising a metal shell, an insulating cap supported by said shell and a metal end contact supported by said cap, said shell being directly mounted on said bulb at one. end and having a plurality of tongues extending from the opposite end, said tongues extending through apertures in said insulating cap and being bent back upon said cap, one of said leading-in conductors being clamped between said shell and insulating.-

cap and the end of another being clamped becap. I

4. In an electrical device, the combination of a glass bulb having mounted therein an electrical energy translation element and leading-in conductors extending therefrom of a base comprising a metal shell, an insulating cap supported by said shell and a metal end contact supported by said can, said shell being directly mounted on said bulb at one end and having a re-entrant sleeve at the oppodte end which engages an annular shoulder portion of said insulating cap, the outer edge of said shell being spun over the rim of said insulating cap to firmly hold said cap in place, one of said leading-in conductors being clamped to said shell by said insulating can and the end of another being clamped between said metal end contact and said insulating cap.

5. In an electrical device. the combination of a glass bulb having mounted therein an electrical energy translation element and leading-in conductors extending therefrom of, a base comprising a metal shell, an insulating can supportll by said shell and a metal end contact supported by said cap, said shell being directly mounted on said bulb at one end and having a re-entrant sleeve at the opposite end comprising a plurality of 'springy fingers, an annular shoulder m at the bottom of said insulating cap, and an annular groove on the outside of said shoulder" mom in. mien.

WALTER J. GIIGER. 1Q 

